Cold Blooded Cunning: The first time the Yuan-Ti attacks an enemy during a battle, its crit range for that attack expands by 2 (to a maximum of 18+).

Nastier SpecialBlock Lotus Poison: If the Yuan-Ti makes a Melee or Range attack and rolls 16+ to hit, the creature is poisoned with the essence of the Black Lotus, they must begin making last gasp saves as their heart begins to stop!